package s3api

import (
	"context"
	"fmt"
	"strings"
	"testing"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/credentials"
	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/aws/aws-sdk-go-v2/service/s3/types"
	"github.com/k0kubun/pp"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// S3TestConfig holds configuration for S3 tests
type S3TestConfig struct {
	Endpoint      string
	AccessKey     string
	SecretKey     string
	Region        string
	BucketPrefix  string
	UseSSL        bool
	SkipVerifySSL bool
}

// Default test configuration - should match s3tests.conf
var defaultConfig = &S3TestConfig{
	Endpoint:      "http://localhost:8333", // Default SeaweedFS S3 port
	AccessKey:     "some_access_key1",
	SecretKey:     "some_secret_key1",
	Region:        "us-east-1",
	BucketPrefix:  "test-versioning-",
	UseSSL:        false,
	SkipVerifySSL: true,
}

// getS3Client creates an AWS S3 client for testing
func getS3Client(t *testing.T) *s3.Client {
	cfg, err := config.LoadDefaultConfig(context.TODO(),
		config.WithRegion(defaultConfig.Region),
		config.WithCredentialsProvider(credentials.NewStaticCredentialsProvider(
			defaultConfig.AccessKey,
			defaultConfig.SecretKey,
			"",
		)),
		config.WithEndpointResolverWithOptions(aws.EndpointResolverWithOptionsFunc(
			func(service, region string, options ...interface{}) (aws.Endpoint, error) {
				return aws.Endpoint{
					URL:               defaultConfig.Endpoint,
					SigningRegion:     defaultConfig.Region,
					HostnameImmutable: true,
				}, nil
			})),
	)
	require.NoError(t, err)

	return s3.NewFromConfig(cfg, func(o *s3.Options) {
		o.UsePathStyle = true // Important for SeaweedFS
	})
}

// getNewBucketName generates a unique bucket name
func getNewBucketName() string {
	timestamp := time.Now().UnixNano()
	return fmt.Sprintf("%s%d", defaultConfig.BucketPrefix, timestamp)
}

// createBucket creates a new bucket for testing
func createBucket(t *testing.T, client *s3.Client, bucketName string) {
	_, err := client.CreateBucket(context.TODO(), &s3.CreateBucketInput{
		Bucket: aws.String(bucketName),
	})
	require.NoError(t, err)
}

// deleteBucket deletes a bucket and all its contents
func deleteBucket(t *testing.T, client *s3.Client, bucketName string) {
	// First, delete all objects and versions
	err := deleteAllObjectVersions(t, client, bucketName)
	if err != nil {
		t.Logf("Warning: failed to delete all object versions: %v", err)
	}

	// Then delete the bucket
	_, err = client.DeleteBucket(context.TODO(), &s3.DeleteBucketInput{
		Bucket: aws.String(bucketName),
	})
	if err != nil {
		t.Logf("Warning: failed to delete bucket %s: %v", bucketName, err)
	}
}

// deleteAllObjectVersions deletes all object versions in a bucket
func deleteAllObjectVersions(t *testing.T, client *s3.Client, bucketName string) error {
	// List all object versions
	paginator := s3.NewListObjectVersionsPaginator(client, &s3.ListObjectVersionsInput{
		Bucket: aws.String(bucketName),
	})

	for paginator.HasMorePages() {
		page, err := paginator.NextPage(context.TODO())
		if err != nil {
			return err
		}

		var objectsToDelete []types.ObjectIdentifier

		// Add versions
		for _, version := range page.Versions {
			objectsToDelete = append(objectsToDelete, types.ObjectIdentifier{
				Key:       version.Key,
				VersionId: version.VersionId,
			})
		}

		// Add delete markers
		for _, deleteMarker := range page.DeleteMarkers {
			objectsToDelete = append(objectsToDelete, types.ObjectIdentifier{
				Key:       deleteMarker.Key,
				VersionId: deleteMarker.VersionId,
			})
		}

		// Delete objects in batches
		if len(objectsToDelete) > 0 {
			_, err := client.DeleteObjects(context.TODO(), &s3.DeleteObjectsInput{
				Bucket: aws.String(bucketName),
				Delete: &types.Delete{
					Objects: objectsToDelete,
					Quiet:   aws.Bool(true),
				},
			})
			if err != nil {
				return err
			}
		}
	}

	return nil
}

// enableVersioning enables versioning on a bucket
func enableVersioning(t *testing.T, client *s3.Client, bucketName string) {
	_, err := client.PutBucketVersioning(context.TODO(), &s3.PutBucketVersioningInput{
		Bucket: aws.String(bucketName),
		VersioningConfiguration: &types.VersioningConfiguration{
			Status: types.BucketVersioningStatusEnabled,
		},
	})
	require.NoError(t, err)
}

// checkVersioningStatus verifies the versioning status of a bucket
func checkVersioningStatus(t *testing.T, client *s3.Client, bucketName string, expectedStatus types.BucketVersioningStatus) {
	resp, err := client.GetBucketVersioning(context.TODO(), &s3.GetBucketVersioningInput{
		Bucket: aws.String(bucketName),
	})
	require.NoError(t, err)
	assert.Equal(t, expectedStatus, resp.Status)
}

// putObject puts an object into a bucket
func putObject(t *testing.T, client *s3.Client, bucketName, key, content string) *s3.PutObjectOutput {
	resp, err := client.PutObject(context.TODO(), &s3.PutObjectInput{
		Bucket: aws.String(bucketName),
		Key:    aws.String(key),
		Body:   strings.NewReader(content),
	})
	require.NoError(t, err)
	return resp
}

// headObject gets object metadata
func headObject(t *testing.T, client *s3.Client, bucketName, key string) *s3.HeadObjectOutput {
	resp, err := client.HeadObject(context.TODO(), &s3.HeadObjectInput{
		Bucket: aws.String(bucketName),
		Key:    aws.String(key),
	})
	require.NoError(t, err)
	return resp
}

// TestBucketListReturnDataVersioning is the Go equivalent of test_bucket_list_return_data_versioning
func TestBucketListReturnDataVersioning(t *testing.T) {
	client := getS3Client(t)
	bucketName := getNewBucketName()

	// Create bucket
	createBucket(t, client, bucketName)
	defer deleteBucket(t, client, bucketName)

	// Enable versioning
	enableVersioning(t, client, bucketName)
	checkVersioningStatus(t, client, bucketName, types.BucketVersioningStatusEnabled)

	// Create test objects
	keyNames := []string{"bar", "baz", "foo"}
	objectData := make(map[string]map[string]interface{})

	for _, keyName := range keyNames {
		// Put the object
		putResp := putObject(t, client, bucketName, keyName, keyName) // content = key name

		// Get object metadata
		headResp := headObject(t, client, bucketName, keyName)

		// Store expected data for later comparison
		objectData[keyName] = map[string]interface{}{
			"ETag":          *headResp.ETag,
			"LastModified":  *headResp.LastModified,
			"ContentLength": headResp.ContentLength,
			"VersionId":     *headResp.VersionId,
		}

		// Verify version ID was returned
		require.NotNil(t, putResp.VersionId)
		require.NotEmpty(t, *putResp.VersionId)
		assert.Equal(t, *putResp.VersionId, *headResp.VersionId)
	}

	// List object versions
	resp, err := client.ListObjectVersions(context.TODO(), &s3.ListObjectVersionsInput{
		Bucket: aws.String(bucketName),
	})
	require.NoError(t, err)

	// Verify we have the expected number of versions
	assert.Len(t, resp.Versions, len(keyNames))

	// Check each version matches our stored data
	versionsByKey := make(map[string]types.ObjectVersion)
	for _, version := range resp.Versions {
		versionsByKey[*version.Key] = version
	}

	for _, keyName := range keyNames {
		version, exists := versionsByKey[keyName]
		require.True(t, exists, "Expected version for key %s", keyName)

		expectedData := objectData[keyName]

		// Compare ETag
		assert.Equal(t, expectedData["ETag"], *version.ETag)

		// Compare Size
		assert.Equal(t, expectedData["ContentLength"], version.Size)

		// Compare VersionId
		assert.Equal(t, expectedData["VersionId"], *version.VersionId)

		// Compare LastModified (within reasonable tolerance)
		expectedTime := expectedData["LastModified"].(time.Time)
		actualTime := *version.LastModified
		timeDiff := actualTime.Sub(expectedTime)
		if timeDiff < 0 {
			timeDiff = -timeDiff
		}
		assert.True(t, timeDiff < time.Minute, "LastModified times should be close")

		// Verify this is marked as the latest version
		assert.True(t, *version.IsLatest)

		// Verify it's not a delete marker
		// (delete markers should be in resp.DeleteMarkers, not resp.Versions)
	}

	// Verify no delete markers
	assert.Empty(t, resp.DeleteMarkers)

	t.Logf("Successfully verified %d versioned objects", len(keyNames))
}

// TestVersioningBasicWorkflow tests basic versioning operations
func TestVersioningBasicWorkflow(t *testing.T) {
	client := getS3Client(t)
	bucketName := getNewBucketName()

	// Create bucket
	createBucket(t, client, bucketName)
	defer deleteBucket(t, client, bucketName)

	// Initially, versioning should be suspended/disabled
	checkVersioningStatus(t, client, bucketName, types.BucketVersioningStatusSuspended)

	// Enable versioning
	enableVersioning(t, client, bucketName)
	checkVersioningStatus(t, client, bucketName, types.BucketVersioningStatusEnabled)

	// Put same object multiple times to create versions
	key := "test-object"
	version1 := putObject(t, client, bucketName, key, "content-v1")
	version2 := putObject(t, client, bucketName, key, "content-v2")
	version3 := putObject(t, client, bucketName, key, "content-v3")

	// Verify each put returned a different version ID
	require.NotEqual(t, *version1.VersionId, *version2.VersionId)
	require.NotEqual(t, *version2.VersionId, *version3.VersionId)
	require.NotEqual(t, *version1.VersionId, *version3.VersionId)

	// List versions
	resp, err := client.ListObjectVersions(context.TODO(), &s3.ListObjectVersionsInput{
		Bucket: aws.String(bucketName),
	})
	require.NoError(t, err)

	// Should have 3 versions
	assert.Len(t, resp.Versions, 3)

	// Only the latest should be marked as latest
	latestCount := 0
	for _, version := range resp.Versions {
		if *version.IsLatest {
			latestCount++
			assert.Equal(t, *version3.VersionId, *version.VersionId)
		}
	}
	assert.Equal(t, 1, latestCount, "Only one version should be marked as latest")

	t.Logf("Successfully created and verified %d versions", len(resp.Versions))
}

// TestVersioningDeleteMarkers tests delete marker creation
func TestVersioningDeleteMarkers(t *testing.T) {
	client := getS3Client(t)
	bucketName := getNewBucketName()

	// Create bucket and enable versioning
	createBucket(t, client, bucketName)
	defer deleteBucket(t, client, bucketName)
	enableVersioning(t, client, bucketName)

	// Put an object
	key := "test-delete-marker"
	putResp := putObject(t, client, bucketName, key, "content")
	require.NotNil(t, putResp.VersionId)

	// Delete the object (should create delete marker)
	deleteResp, err := client.DeleteObject(context.TODO(), &s3.DeleteObjectInput{
		Bucket: aws.String(bucketName),
		Key:    aws.String(key),
	})
	require.NoError(t, err)
	require.NotNil(t, deleteResp.VersionId)

	// List versions to see the delete marker
	listResp, err := client.ListObjectVersions(context.TODO(), &s3.ListObjectVersionsInput{
		Bucket: aws.String(bucketName),
	})
	require.NoError(t, err)

	// Should have 1 version and 1 delete marker
	assert.Len(t, listResp.Versions, 1)
	assert.Len(t, listResp.DeleteMarkers, 1)

	// The delete marker should be the latest
	deleteMarker := listResp.DeleteMarkers[0]
	assert.True(t, *deleteMarker.IsLatest)
	assert.Equal(t, *deleteResp.VersionId, *deleteMarker.VersionId)

	// The original version should not be latest
	version := listResp.Versions[0]
	assert.False(t, *version.IsLatest)
	assert.Equal(t, *putResp.VersionId, *version.VersionId)

	t.Logf("Successfully created and verified delete marker")
}

// TestVersioningConcurrentOperations tests concurrent versioning operations
func TestVersioningConcurrentOperations(t *testing.T) {
	client := getS3Client(t)
	bucketName := getNewBucketName()

	// Create bucket and enable versioning
	createBucket(t, client, bucketName)
	defer deleteBucket(t, client, bucketName)
	enableVersioning(t, client, bucketName)

	// Concurrently create multiple objects
	numObjects := 10
	objectKey := "concurrent-test"

	// Channel to collect version IDs
	versionIds := make(chan string, numObjects)
	errors := make(chan error, numObjects)

	// Launch concurrent puts
	for i := 0; i < numObjects; i++ {
		go func(index int) {
			content := fmt.Sprintf("content-%d", index)
			resp, err := client.PutObject(context.TODO(), &s3.PutObjectInput{
				Bucket: aws.String(bucketName),
				Key:    aws.String(objectKey),
				Body:   strings.NewReader(content),
			})
			if err != nil {
				errors <- err
				return
			}
			versionIds <- *resp.VersionId
		}(i)
	}

	// Collect results
	var collectedVersionIds []string
	for i := 0; i < numObjects; i++ {
		select {
		case versionId := <-versionIds:
			t.Logf("Received Version ID %d: %s", i, versionId)
			collectedVersionIds = append(collectedVersionIds, versionId)
		case err := <-errors:
			t.Fatalf("Concurrent put failed: %v", err)
		case <-time.After(30 * time.Second):
			t.Fatalf("Timeout waiting for concurrent operations")
		}
	}

	// Verify all version IDs are unique
	versionIdSet := make(map[string]bool)
	for _, versionId := range collectedVersionIds {
		assert.False(t, versionIdSet[versionId], "Version ID should be unique: %s", versionId)
		versionIdSet[versionId] = true
	}

	// List versions and verify count
	listResp, err := client.ListObjectVersions(context.TODO(), &s3.ListObjectVersionsInput{
		Bucket: aws.String(bucketName),
	})
	pp.Println(listResp)
	require.NoError(t, err)
	assert.Len(t, listResp.Versions, numObjects)

	t.Logf("Successfully created %d concurrent versions with unique IDs", numObjects)
}